1. Technical Field
This description generally relates to a reconstituted semiconductor wafer with semiconductor chips embedded within that have been treated in a plasma chamber.
2. Description of the Related Art
Typically, after a semiconductor chip is manufactured, it must further be processed and encapsulated in a package that functions to protect the chip and to establish electrical connections from the chip to the external environment. Two methods by which a semiconductor chip may be packaged include fan-in and fan-out packages.
Fan-in methods of semiconductor packaging usually result in a semiconductor package that is essentially the same size as the semiconductor chip. This is because fan-in methods use wafer level packaging techniques that build the semiconductor package on top of the semiconductor wafer after the chips have been created. Due to the proximity of each semiconductor chip to one another on the wafer there is limited space for making electrical connections laterally, so packages are built vertically. As a result, and because of the chip size, a limited amount of space is available for electrical contacts.
Fan-out methods of semiconductor packaging are not restricted by the size of the semiconductor chip in determining the number of electrical contacts to the external environment. This is because fan-out semiconductor packages have a larger footprint area than that of the semiconductor chips within. Typically, during fan-out methods of semiconductor packaging, the semiconductor chips are cut from the semiconductor wafer after the chips are manufactured. The cut chips are subsequently placed on an adhesive layer and formed into a reconstituted wafer. Since the semiconductor chips were not formed on the reconstituted wafer initially, they must be either permanently or temporarily affixed to the surface to form the reconstituted wafer.
Several known ways of adhering chips to a surface include adhesive glue, adhesive tape, epoxy resin, etc. Even with known methods of affixing chips to a reconstituted wafer, however, there is a possibility that the chips will move due to various stresses and forces during the packaging process. For example, the upper surface of the semiconductor wafer is usually a passivation layer that may be made of various different types of materials. Each type of passivation layer may be designed to adhere to different types of adhesive layers during semiconductor chip packaging. As a result, when the chip packaging reaches an encapsulation process, chips that are not well adhered may be knocked loose, resulting in what is known as flying dies (i.e., flying chips). Flying dies are undesirable because the number of viable semiconductor packages produced is reduced and the cost of manufacturing semiconductor packages is increased.